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Volumn 19, Issue 5, 1998, Pages 475-487

Effect of inclusion of electron correlation in MM3 studies of cyclic conjugated compounds

Author keywords

Conjugated polyenes; Correlation energies; Molecular mechanics

Indexed keywords


EID: 0000821401     PISSN: 01928651     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1096-987X(19980415)19:5<475::AID-JCC1>3.0.CO;2-J     Document Type: Article
Times cited : (18)

References (28)
  • 1
    • 0024821263 scopus 로고
    • The MM3 force field is described in J. Am. Chem. Soc. 111, 8551, 8566, 8576 (1989), and in subsequent publications. The MM3 program is available from Tripos Associates (1699 South Hanley Road, St. Louis, MO 63144) to all users or from the Quantum Chemistry Program Exchange (Mr. Richard Counts, Indiana University, Bloomington, IN 47405) for academic users.
    • (1989) J. Am. Chem. Soc. , vol.111 , pp. 8551
  • 9
    • 85034468420 scopus 로고    scopus 로고
    • note
    • (b) The block-diagonal minimization converges quickly and reliably when far from the minimum energy structure, but the full-matrix minimization converges more rapidly near the minimum. It is advantageous to use the former minimization method with a crude starting geometry, followed by the latter when near the minimum. However, either method may end up at a saddlepoint or even a hilltop in the potential surface. Whether the structure corresponds to a minimum, a saddlepoint, or a hilltop can be determined from the calculated vibrational frequencies. If they are all real, the molecule is at an energy minimum, whereas imaginary frequencies indicate otherwise. This information is only available from the full-matrix minimization. In MM2 and earlier versions of MM3, the full-matrix minimization was not incorporated, and occasionally structures that were reported as local minimum structures in earlier articles were later found to be saddlepoint or hilltop structures.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.